"""
输出格式
1、使用占位符输出%,占位符有%s,%d,%f
2、xxx.format()
3、f"{}"
"""
import time
import  datetime
msg = 'course:%s' % ('语文')
print(msg)
msg = 'my name is{0},year is{1}'.format('苏泽', 20)
print(msg)
name = '刘梦婉'
old = '21'
msg = f'my lover is{name},her year is {old}'
print(msg)

while True:
    print(datetime.datetime.now())
    time.sleep(0.1)